Automatic frame turnover machine and frame turnover method

The invention relates to an automatic frame turnover machine and a frame turnover method.The automatic frame turnover machine comprises a turnover machine frame, the turnover machine frame is slidably provided with two shear fork lifting structures, and the two shear fork lifting structures are distributed in the length direction of the turnover machine frame at intervals; the telescopic end of each scissor fork lifting structure is provided with the corresponding chain turner; and the two chain angle adjusters are connected between each scissor fork lifting structure and each chain turner, and the chain angle adjusters can adjust the chains of the chain turners connected with the chain angle adjusters to stretch or retract. The device can adapt to frames with different lengths; the chain angle adjuster is used for adjusting the chain to stretch or retract, so that the chain is in a stretching state when penetrating into and exiting from the frame, and automatic sleeving is facilitated; meanwhile, the chain a